Where should NIS be installed on x64 W7?

Hi. I've just taken the plunge and upgraded to Win7, and for the first time I've installed a 64-bit OS, so I'm new to it. Just installed Norton Internet Security on the machine. Norton reports it as being x64 compatible, however, it's installed in the C:\Program Files (x86) directory. Why is that? Surely if it's x64 compatible it should be in the normal Prohram Files. Some help please.